Multilayer ceramic electronic component

ABSTRACT

A multilayer ceramic electronic component includes a ceramic body including a dielectric layer and a plurality of internal electrodes disposed to face each other with the dielectric layer interposed therebetween and external electrodes disposed on external surfaces of the ceramic body and electrically connected to the internal electrodes, respectively. The external electrode includes electrode layers electrically connected to the internal electrodes, and plating layers disposed on the electrode layers. At least one point, at which slopes of tangent lines of one of the electrode layers and the plating layers are opposite to each other, is disposed in a region within a range of ±0.2 BW around a point (0.5 BW) that is a halfway point of an overall width BW of the electrode layers disposed on the first surface or the second surface of the ceramic body.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/179,528 filed Nov. 2, 2018 which claims benefit of priority to KoreanPatent Application No. 10-2018-0106636 filed on Sep. 6, 2018 in theKorean Intellectual Property Office, the disclosures of each areincorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to a multilayer ceramic electroniccomponent, and more particularly, to a method of fabricating amultilayer ceramic electronic component having excellent reliability.

BACKGROUND

In general, an electronic component using a ceramic material, such as acapacitor, an inductor, a piezoelectric element, a varistor, athermistor, or the like, includes a ceramic body formed of a ceramicmaterial, internal electrodes provided inside the ceramic body, andexternal electrodes provided on surfaces of the ceramic body andrespectively connected to the internal electrodes.

Among multilayer ceramic electronic components, a multilayer ceramiccapacitor includes a plurality of laminated dielectric layers, internalelectrodes disposed to oppose each other with the dielectric layerinterposed therebetween, and external electrodes electrically connectedto internal electrodes.

Multilayer ceramic capacitors have been widely used as components inmobile communications devices such as computers, personal dataassistants (PDAs), mobile phones, and the like, due to advantagesthereof such as compactness, high capacitance, ease of mounting, and thelike.

With the recent trend toward high performance and lightweight, thinness,shortness, and small size of electronic devices, electronic componentshave also been required to have a small size, high performance, andultrahigh capacitance.

According to high capacitance and miniaturization of a multilayerceramic capacitor, there is need for a technique to significantlyincrease capacitance per unit volume.

In the case of an internal electrode, high capacitance should beimplemented by increasing the number of laminations, achieved bysignificantly decreasing the volume of the internal electrode whilesignificantly increasing an area of the internal electrode.

Due to high capacitance and miniaturization of a multilayer ceramiccapacitor, securing reliability, in detail, moisture-resistancereliability is becoming an important issue.

SUMMARY

An aspect of the present disclosure is to provide a multilayer ceramicelectronic component and a method of fabricating a multilayer ceramicelectronic component having excellent reliability.

According to an aspect of the present disclosure, a multilayer ceramicelectronic component includes a ceramic body including a dielectriclayer and a plurality of internal electrodes disposed to oppose eachother with the dielectric layer interposed therebetween, the ceramicbody having a first surface and a second surface disposed to face eachother in a first direction, a third surface and a fourth surfaceconnected to the first surface and the second surface and opposing eachother in a second direction, and a fifth surface and a sixth surfaceconnected to the first surface to the fourth surface and opposing eachother in a third direction, and an external electrode disposed onexternal surfaces of the ceramic body and electrically connected to theinternal electrodes. The external electrode includes electrode layerselectrically connected to the internal electrodes and plating layersdisposed on the electrode layers, and the electrode layers and theplating layers extend to the first surface and the second surface of theceramic body. At least one point, at which slopes of tangent lines ofone of the electrode layers and the plating layers are opposite to eachother, is disposed in a region within a range of ±0.2 BW around a point(0.5 BW) that is a halfway point of an overall width BW of the electrodelayers disposed on the first surface or the second surface of theceramic body.

According to an aspect of the present disclosure, a multilayer ceramicelectronic component includes a ceramic body including dielectric layersand first and second internal electrodes disposed to face each otherwith the dielectric layers interposed therebetween, the ceramic bodyhaving a first surface and a second surface opposing each other in afirst direction, a third surface and a fourth surface connected to thefirst surface and the second surface and opposing each other in a seconddirection, and a fifth surface and a sixth surface connected to thefirst surface to the fourth surface and opposing each other in a thirddirection; and an external electrode including a first electrode layerin contact with the first internal electrodes, a second electrode layerdisposed on the first electrode layer and exposing an end portion of thefirst electrode layer, and first and second plating layers disposed onthe first and second electrode layers. The first and second electrodelayers and the first and second plating layers extend from the thirdsurface to the first surface and the second surface of the ceramic body,and at least one of the first electrode layer and the first and secondplating layers has a dimple in a region within a range of ±0.2 BW, inthe second direction, around a point (0.5 BW) that is a halfway point ofan overall width BW, in the second direction, of the first electrodelayer disposed on the first surface or the second surface of the ceramicbody.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a perspective view of a multilayer ceramic capacitor accordingto an exemplary embodiment in the present disclosure;

FIG. 2 is a perspective view illustrating an appearance of a ceramicbody according to an exemplary embodiment in the present disclosure;

FIG. 3 is a cross-sectional view taken along line I-I′ in FIG. 1; and

FIG. 4 is an enlarged view of region “E” in FIG. 3.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments in the present disclosure will bedescribed in detail, with reference to the accompanying drawings, wherethose components are rendered using the same reference number that arethe same or are in correspondence, regardless of the figure number, andredundant explanations are omitted.

An exemplary embodiment in the present disclosure relates to a ceramicelectronic component. An electronic component using a ceramic materialmay be a capacitor, an inductor, a piezoelectric component, a varistor,a thermistor, or the like. Below, a multilayer ceramic capacitor will bedescribed as an example of the ceramic electronic component.

FIG. 1 is a perspective view of a multilayer ceramic capacitor accordingto an exemplary embodiment in the present disclosure.

FIG. 2 is a perspective view illustrating an appearance of a ceramicbody according to an exemplary embodiment in the present disclosure.

FIG. 3 is a cross-sectional view taken along line I-I′ in FIG. 1.

FIG. 4 is an enlarged view of region “E” in FIG. 3.

Referring to FIGS. 1 to 4, a multilayer ceramic capacitor 100 accordingto an exemplary embodiment includes a ceramic body 110, internalelectrodes 121 and 122 disposed inside the ceramic body 110, andexternal electrodes 131 and 132 disposed on an external surface of theceramic body 110.

In FIG. 1, a ‘length direction’ of the multilayer ceramic capacitor 100may be defined as an ‘L’ direction, a ‘width direction’ thereof may bedefined as a ‘W’ direction, and a ‘thickness direction’ thereof may bedefined as a ‘T’ direction. The ‘thickness direction’ may be used ashaving the same concept as a direction in which dielectric layers arelaminated, for example, a ‘lamination direction.’

The ceramic body 100 may have a hexahedral shape or a similar shape, butthe shape of the body 100 is not limited thereto.

The ceramic body 110 may include a first surface S1 and a second surfaceS2 disposed to oppose each other in a first direction, a third surfaceS3 and a fourth surface S4 connecting the first surface S1 and thesecond surface S2 and disposed to oppose each other in a seconddirection, and a fifth surface S5 and a sixth surface S6 connecting thefirst surface S1 to the fourth surface S4 and disposed to oppose eachother in a third direction.

The first surface S1 and the second surface S2 are surfaces opposing toeach other in the thickness direction of the ceramic body 110, the firstdirection. The third surface S3 and the fourth surface S4 may be definedas surfaces opposing each other in the length direction of the ceramicbody 110, the second direction, and the fifth surface S5 and the sixthsurface S6 may be defined as surfaces opposing to each other in thewidth direction of the ceramic body 110, the third direction.

The plurality of internal electrodes 121 and 122 disposed inside theceramic body 110 may have ends exposed through the third surface S3 orthe fourth surface S4.

The internal electrodes 121 and 122 may include a pair of a firstelectrode 121 and a second electrode 122.

One end of the first internal electrode 121 may be exposed through thethird surface S3, and one end of the second internal electrode 122 maybe exposed through the fourth surface S4.

The other end of the first internal electrode 121 and the other end ofthe second internal electrode 122 may be disposed at regular intervalsfrom the fourth surface S4 or the third surface S3, which will bedescribed in detail later.

The first and second external electrodes 131 and 132 may be provided onthe third surface S3 and the fourth surface S4 of the ceramic body 110to be electrically connected to the internal electrodes 121 and 122.

Each of the internal electrodes may have a thickness of, for example,0.4 micrometer (μm) or less, but the thickness thereof is not limitedthereto.

According to an exemplary embodiment, at least 200 dielectric layerseach including an internal electrode disposed thereon may be laminated.

According to an exemplary embodiment, the ceramic body 110 may include aplurality of dielectric layers 111 laminated therein.

A plurality of dielectric layers 111 forming the ceramic body 110 are ina sintered state. Adjacent dielectric layers 111 may be integrated witheach other such that boundaries therebetween may not be readilyapparent.

The dielectric layer 111 may be formed by sintering a ceramic greensheet including a ceramic powder.

The ceramic powder is not limited as long as it is typically used in theart.

The ceramic powder may include, for example, a barium titanate(BaTiO₃)-based ceramic powder, but is not limited thereto.

The BaTiO₃-based ceramic powder may be, for example,(Ba_(1-x)Ca_(x))TiO₃, Ba(Ti_(1-y)Ca_(y))O₃,(Ba₁Ca_(x))(Ti_(1-y)Zr_(y))O₃, Ba(Ti_(1-y)Zr_(y))O₃ or the like, inwhich some of calcium (Ca), zirconium (Zr), and the like are employed inBaTiO₃, but is not limited thereto.

The ceramic green sheet may include a transition metal, a rare earthelement, magnesium (Mg), aluminum (Al), and the like, in addition to theceramic powder.

A thickness of the dielectric layer 111 may appropriately vary dependingon a capacitance design of a multilayer ceramic capacitor.

For example, the thickness of the dielectric layer 111 provided betweentwo internal electrode layers adjacent to each other after beingsintered may be 0.4 μm or less, but the thickness thereof is not limitedthereto.

In an exemplary embodiment, the thickness of the dielectric layer 111may refer to an average thickness.

An average thickness of the dielectric layer 111 may be measured byscanning a cross section in the length direction of the ceramic body1110 using a scanning electronic microscope (SEM), as shown in FIG. 3.

For example, the average thickness may be obtained by measuring thethicknesses at 30 equidistant points in a length direction, on an imageof any dielectric layer, extracted from the image obtained by scanning across section in length-thickness directions (L-T), cut in a centralportion in a width direction W of the ceramic body 110 and averaging themeasured thickness values.

The 30 equidistant points may be measured in a capacitance formingportion, a region in which the first and second internal electrodes 121and 122 overlap each other.

If the measurement of average thickness is performed on up to ten ormore dielectric layers, the average thickness of the dielectric layermay be further generalized.

The ceramic body 110 may include an active portion A as a portioncontributing to formation of capacitance of a capacitor and a top coverportion C1 and a bottom cover portion C2, as a margin portion,respectively disposed above and below the active portion A.

The active portion A may be formed by repeatedly laminating theplurality of first and second internal electrodes 121 and 122 with thedielectric layer 111 interposed therebetween.

The top cover portion C1 and the bottom cover portion C2 may have thesame material and structure as the dielectric layer 111, except thatthey do not include an internal electrode.

For example, the top cover portion C1 and the bottom cover portion C2may include a ceramic material such as a barium titanate (BaTiO₃)-basedceramic material.

The top cover portion C1 and the bottom cover portion C2 may be formedby vertically laminating a single dielectric layer or two or moredielectric layers on top and bottom surfaces of the active portion A.The cover portion 112 may basically serve to prevent damage of aninternal electrode caused by a physical or chemical stress.

Each of the top cover portion C1 and the bottom cover portion C2 mayhave a thickness of 20 μm or less, but the thickness thereof is notlimited thereto.

With the recent trend toward high performance and lightweight, thinness,shortness, and small size of electronic devices, electronic componentshave also been required to have s small size, high performance, andultrahigh capacitance. Accordingly, top and bottom cover portionsdisposed inside a ceramic body are decreasing in thickness.

In the case in which each of the first cover portion C1 and the bottomcover portion C2 has a thickness of 20 μm or less, external moisture anda plating solution may readily permeate through the thin cover portionsC1 and C2 to increase probability of poor moisture-resistancereliability.

According to an exemplary embodiment, an external electrode may bemultiply coated to prevent disconnection of an external electrodedisposed on a corner portion of the ceramic body. Moreover, pointshaving opposite slopes of tangents may be disposed in a certain area ofan electrode layer and a plating layer disposed on top and bottomsurface of the ceramic body to improve the moisture-resistancereliability.

For example, a feature of a high-capacitance micro multilayer ceramiccapacitor according to exemplary embodiment is that an externalelectrode is multiply coated to improve moisture-resistance reliabilitywhen each of the upper cover portion C1 and the bottom cover portion C2has a small thickness of 20 μm or less.

Accordingly, in a conventional multilayer ceramic capacitor in which athickness of each of an upper cover portion C1 and a lower cover portionC2 is more than 20 μm, moisture-resistance reliability is notsignificantly problematic, by multiply coating an external electrode,similarly to an exemplary embodiment, although points having oppositeslopes of tangents are not disposed in a certain area of an electrodelayer and a plating layer disposed on top and bottom surface of theceramic body.

The first and second internal electrodes 121 and 122 may be formed usinga conductive paste containing at least one of, for example, silver (Ag),lead (Pb), platinum (Pt), nickel (Ni), and copper (Cu), but a materialthereof is not limited thereto.

A multilayer ceramic capacitor according to an exemplary embodiment mayinclude a first external electrode 131 electrically connected to thefirst internal electrode 121 and a second external electrode 132electrically connected to the second internal electrode 122.

The first and second external electrodes 131 and 132 may be electricallyconnected to the first and second internal electrodes 121 and 122 toform capacitance, and the second external electrode 132 may be connectedto a potential different from a potential connected to the firstexternal electrode 131.

The first and second external electrodes 131 and 132 may be disposed onthe third surface S3 and the fourth surface S4 in the length directionthat is the second direction of the ceramic body 110, respectively andmay extend to the first surface S1 and the second surface S2 in thethickness direction that is the first direction of the ceramic body 110.

The external electrode 131 is disposed on an external surface of theceramic body 111 and includes electrode layers 131 a and 131 belectrically connected to the internal electrodes 121 and plating layers131 c and 131 d disposed on the electrode layers 131 a and 131 b. Theexternal electrode 132 is disposed on another external surface of theceramic body 111 and includes electrode layers 132 a and 132 belectrically connected to the internal electrodes 122 and plating layers132 c and 132 d disposed on the electrode layers 132 a and 132 b.

The external electrodes 131 and 132 include a first external electrode131 and a second external electrode 132 respectively disposed one sideand the other side of the ceramic body 111.

The electrode layers 131 a, 131 b, 132 a, and 132 b may include aconductive metal and a glass.

A conductive metal used in the electrode layers 131 a, 131 b, 132 a, and132 b is not limited as long as it may be electrically connected to theinternal electrode to form capacitance. The conductive metal may be atleast one selected from the group consisting of, for example, copper(Cu), silver (Ag), nickel (Ni), and alloys thereof.

The electrode layers 131 a, 131 b, 132 a, and 132 b may be formed bycoating a conductive paste prepared by adding glass frit to theconductive metal powder and sintering the coated conductive paste.

For example, the electrode layers 131 a, 131 b, 132 a, and 132 b may besintered electrodes formed by sintering a paste containing a conductivemetal.

The conductive metal included in the electrode layers 131 a, 131 b, 132a, and 132 b is electrically conducted to the first and second internalelectrodes 121 and 122 to implement electrical characteristics.

The glass included in the electrode layers 131 a, 131 b, 132 a, and 132b serve as a sealant with the conductive metal to block externalmoisture.

The first external electrode 131 is disposed one surface in the lengthdirection L that is the second direction of the ceramic body 110 andincludes first electrode layers 131 a and 131 b electrically connectedto the first internal electrode 121 and first plating layers 131 c and131 d disposed on the first electrode layers 131 a and 131 b.

The second external electrode 132 is disposed on the other surface inthe length direction L that is the second direction of the ceramic body110 and includes second electrode layers 132 a and 132 b electricallyconnected to the second internal electrode 122 and second plating layers132 c and 132 d disposed on the second electrode layers 132 a and 132 b.

The electrode layers 131 a, 131 b, 132 a, and 132 b may be disposed onboth side surfaces in the length direction L of the ceramic body 110 andmay extend to portions of the first surface S1 and the second surface S2that are a top surface and a bottom surface of the ceramic body 110.

Plating layers 131 b, 131 c, 132 b, and 132 c may be disposed above theelectrode layers 131 a, 131 b, 132 a, and 132 b.

The electrode layers 131 a, 131 b, 132 a, and 132 b may be formed of thesame conductive metal as the first and second internal electrodes 121and 122, but a material thereof is not limited thereto. For example, theelectrode layers 131 a, 131 b, 132 a, and 132 b may be formed of copper(Cu), silver (Ag), nickel (Ni) or alloys thereof.

The electrode layers 131 a, 131 b, 132 a, and 132 b may be disposed onthe third surface S3 and the fourth surface S4 disposed to oppose eachother in the second direction of the ceramic body 110, respectively, andmay include first layers 131 a and 132 a electrically connected to theinternal electrodes 121 and 122 and second layers 131 b and 132 bdisposed on the first layers 131 a and 132 b in such a manner thatwidths, in the length direction, of the second layers 131 b and 132 bdisposed on the first surface S1 and the second surface S2 are smallerthan widths, in the length direction, of the first layers 131 a and 132a.

The second layers 131 b and 132 b may cover corner portions of theceramic body 110.

According to an exemplary embodiment, since the first layers 131 a and132 a and the second layers 131 b and 132 b that are electrode layerscover the corner portions of the ceramic body 110, external moisture andplating solution may be prevented from permeating the corner portions ofthe ceramic body 110 by multiple coating. Thus, moisture-resistancereliability may be improved.

The plating layers 131 c, 131 d, 132 c, and 132 d may include nickelplating layers 131 c and 132 c and tin plating layers 131 d and 132 ddisposed on the nickel plating layers 131 c and 132 c, but are notlimited thereto.

The plating layers 131 c, 131 d, 132 c, and 132 d may cover end portionsof the first layers 131 a and 132 a.

According to an exemplary embodiment, the electrode layers 131 a, 131 b,132 a, and 132 b and plating layers 131 c, 131 d, 132 c, and 132 dextend to the first surface S1 and the second surface S2 of the ceramicbody 110.

At least one point I_(P), at which the slopes of the tangent lines ofthe electrode layers 131 a and 132 a and the plating layers 131 c, 131d, 132 c, and 132 d are opposite to each other, is disposed in a regionwithin a range of ±0.2 BW in the length direction around a point (0.5BW) that is a halfway point of an overall width BW, in the lengthdirection, of the electrode layers disposed on the first surface S1 orthe second surface S2 of the ceramic body 110. At least one point I_(P),a dimple, is disposed in a region within a range of ±0.2 BW in thelength direction around a point (0.5 BW) that is a halfway point of anoverall width BW, in the length direction, of the electrode layersdisposed on the first surface S1 or the second surface S2 of the ceramicbody 110.

The overall width BW of the electrode layers disposed on a first surfaceand a second surface of the ceramic body is a width, in the lengthdirection, of the first layers 131 a and 132 a.

As mentioned above, at least one point I_(P), at which the slopes of thetangent lines of the electrode layers 131 a and 132 a and the platinglayers 131 c, 131 d, 132 c, and 132 d are opposite to each other, isdisposed in a region within a range of ±0.2 BW around a point (0.5 BW)that is a halfway point of the overall width BW of the electrode layersdisposed on the first surface S1 or the second the surface S2 of theceramic body 110. Accordingly, there is no disconnection of an externalelectrode disposed on the corner portion of the ceramic body 110 andmoisture-resistance characteristics may be enhanced to improvereliability.

The region within a range of ±0.2 BW around a point (0.5 BW) that is ahalfway point of the overall width BW of the electrode layers disposedon the first surface S1 or the second surface S2 of the ceramic body 110is a region occupying 40 percent of the overall width BW of the firstlayers 131 a and 132 a, as shown in FIG. 4, and may be designated by 0.4BW.

There may be at least two points I_(F), at which the slopes of thetangent lines of the electrode layers 131 a and 132 a and the platinglayers 131 c, 131 d, 132 c, and 132 d are opposite to each other, in theregion within a range of ±0.2 BW around the point (0.5 BW) that is ahalfway point of the overall width BW of the electrode layers disposedon the first surface S1 or the second surface S2 of the ceramic body110.

In a product to which a thin dielectric film and an internal electrodeare applied (the dielectric layer 111 having a thickness of 0.4 μm orless and each of the first and second electrodes 121 and 122 having athickness of 0.4 μm or less after being sintered), moisture-resistancereliability may be degraded.

Accordingly, when the dielectric layer 111 has a thickness of 0.4 μm orless and each of the first and second electrodes 121 and 122 has athickness of 0.4 μm or less, an electrode layer should be multiplycoated and at least one point I_(F), at which the slopes of the tangentlines of the electrode layers 131 a and 132 a and the plating layers 131c, 131 d, 132 c, and 132 d are opposite to each other, should bedisposed in the region within a range of ±0.2 BW around the point (0.5BW) that is a halfway point of the overall width BW of the electrodelayers. Thus, degradation of the moisture-resistance reliability may beprevented.

The term “thin film” used herein means that a dielectric layer and aninternal electrode have thicknesses smaller than thicknesses of adielectric layer and an internal electrode of a conventional product,and also means that each of the dielectric layer 111 and the first andsecond internal electrodes 121 and 122 has a thickness of 0.4 μm orless.

In an exemplary embodiment, the point I_(P) at which the slopes of thetangent lines of the electrode layers 131 a and 132 a and the platinglayers 131 c, 131 d, 132 c, and 132 d are opposite to each other may bea point at which slopes of tangent lines changes from a negative valueto a positive value.

For example, as shown in FIG. 4, a slope of tangent ST1 may have anegative value in a region previous from the point I_(P) at which theslopes of the tangent lines of the electrode layers 131 a and 132 a andthe plating layers 131 c, 131 d, 132 c, and 132 d are opposite to eachother. After passing through the point I_(P), a slope of tangent ST2 mayhave a positive value.

In an exemplary embodiment, at least one point I_(P) at which the slopesof the tangent lines of the electrode layers 131 a and 132 a and theplating layers 131 c, 131 d, 132 c, and 132 d change from a negativevalue to a positive value is disposed in the region within a range of±0.2 BW around the point (0.5 BW) that is a halfway point of the overallwidth BW of the electrode layers, among the electrode layers disposed onthe first surface S1 or the second surface S2 of the ceramic body 110.

As a result, moisture-resistance reliability of a multilayer ceramicelectronic component may be improved.

Hereinafter, a method of fabricating a multilayer ceramic capacitoraccording to an exemplary embodiment will be described below.

A plurality of ceramic green sheets may be prepared according to anexemplary embodiment.

To form the ceramic green sheet, a slurry may be prepared by mixing aceramic powder, a binder, a solvent, and the like. The slurry may shapedbe in the form a sheet having a thickness of several micrometers by adoctor blade technique. Then, the ceramic green sheet may be sintered toform a dielectric layer 111, as shown in FIG. 2.

The ceramic green sheet may have a thickness of 0.6 μm. Accordingly,after the sintering, the dielectric layer may have a thickness of 0.4 μmor less.

Next, a conductive paste for an internal electrode may be coated on theceramic green sheet to form an internal electrode pattern. The internalelectrode pattern may be formed by means of a screen printing method, agravure printing method, or the like.

The conductive paste for an internal electrode may include a conductivemetal and an additive, and the additive may at least one of a non-metaloxide and a metal oxide.

The conductive metal may include nickel. The additive may include bariumtitanate or strontium titanate as the metal oxide.

The internal electrode pattern may have a thickness of 0.5 μm or less.Accordingly, after the sintering, the internal electrode may have athickness of 0.4 μm or less.

The ceramic green sheet, on which the internal electrode pattern isformed, may be laminated and may be pressurized in a laminated directionto be compressed to form a ceramic-laminated structure in which theinternal electrode pattern is formed.

The ceramic-laminated structure may be cut in each region correspondingto a single capacitor to form chips.

In this case, the ceramic-laminated structure may be cut in such amanner that ends of internal electrode patterns are alternately exposedthrough side surfaces thereof.

The ceramic-laminated structure formed into chips may be sintered toform a ceramic body.

The sintering process may be performed in a reducing atmosphere.Additionally, the sintering process may be performed by controlling atemperature-increase speed. The temperature-rising speed may be 30°C./60 s to 50° C./60 s at 700° C. or less.

An external electrode may be formed to be electrically connected to aninternal electrode exposed to a side surface of the ceramic body whilecovering the side surface of the ceramic body. A plating layer such asnickel, tin, or the like may be formed on a surface of the externalelectrode.

More specifically, a multilayer ceramic capacitor according to anexemplary embodiment was prepared through a method described below.

Barium titanate powder, ethanol as an organic solvent, and polyvinylbutyral as a binder were mixed and ball-milled to prepare ceramicslurry. A ceramic green sheet was prepared using the ceramic slurry.

A nickel-containing conductive paste for an internal electrode wasprinted on the ceramic green sheet to form an internal electrode. Agreen laminated structure with the internal electrode laminated wasisostatically pressed at temperature of 85° C. and pressure of 1,000kgf/cm².

The compressed green laminated structure was cut to form a green chip.The green chip was maintained in atmosphere at a temperature of 230° C.for 60 hours during a de-binding process. The green chip subjected tothe de-binding process was sintered at temperature of 1,000° C. to forma sintered chip. The sintering process was performed in a reducingatmosphere to prevent oxidation of the internal electrode, and thereducing atmosphere was rendered to be 10⁻¹¹ to 10⁻¹⁰ atm lower than anNi/NiO equilibrium oxygen partial pressure.

An electrode layer was formed outwardly of the sintered chip using apaste for an external electrode including a copper powder and a glasspowder. A nickel plating layer and a tin plating layer were formed onthe electrode layer through electroplating.

A first layer was formed outwardly of the sintered chip using the pastefor an external electrode including a copper powder and a glass powder.A second layer was formed on the first layer to have smaller width thanthe first layer in a length direction of the ceramic body, by using apaste for an external electrode including a copper powder and a glasspowder similar to the copper powder and the glass powder of the firstlayer.

The electrode layer may be doubly coated on the first layer and thesecond layer to doubly form a sintered electrode layer in a cornerportion of the ceramic body. Thus, an uncoated problem of externalelectrode on the corner portion of the ceramic body may be prevented toimprove moisture-resistance reliability.

As described above, according to an exemplary embodiment, an externalelectrode is multiply coated. Thus, there is no disconnection of anexternal electrode disposed on a corner portion of a ceramic body.Further, a point at which slopes of tangent lines are opposite to eachother is disposed in a certain region of an electrode layer and aplating layer disposed on a top surface and a bottom surface of theceramic body. Thus, moisture-resistance characteristics may be enhancedto improve reliability.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A multilayer ceramic electronic componentcomprising: a ceramic body including dielectric layers and a pluralityof internal electrodes disposed to face each other with the dielectriclayers interposed therebetween, the ceramic body having a first surfaceand a second surface opposing each other in a first direction, a thirdsurface and a fourth surface connected to the first surface and thesecond surface and opposing each other in a second direction, and afifth surface and a sixth surface connected to the first surface to thefourth surface and opposing each other in a third direction; and anexternal electrode disposed on external surfaces of the ceramic body andconnected to the internal electrodes, wherein the external electrodeincludes electrode layers connected to the internal electrodes and theelectrode layers extend to the first surface and the second surface ofthe ceramic body, the electrode layers are disposed on one of the thirdsurface and the fourth surface, and include a first layer connected tothe internal electrodes and a second layer disposed on the first layerin such a manner that a width of the second layer disposed on the firstsurface or the second surface of the ceramic body is smaller than awidth of the first layer disposed thereon, at least one point, at whichslopes of tangent lines of one of the first and second layers areopposite to each other, is disposed on the first surface or the secondsurface of the ceramic body, and each of the first layer and the secondlayer is disposed on the one of the third surface and the fourth surfaceand is disposed on the first surface or the second surface.
 2. Themultilayer ceramic electronic component of claim 1, wherein the externalelectrode includes plating layers disposed on the second layer, and theplating layers extend to the first surface and the second surface of theceramic body, and at least one point, at which slopes of tangent linesof one of the plating layers are opposite to each other, is disposed onthe first surface or the second surface of the ceramic body.
 3. Themultilayer ceramic electronic component of claim 2, wherein the at leastone point at which slopes of tangent lines of one of the plating layersare opposite to each other, is disposed in a region within a range of±0.2 BW around a point (0.5 BW) that is a halfway point of an overallwidth BW of the electrode layers disposed on the first surface or thesecond surface of the ceramic body.
 4. The multilayer ceramic electroniccomponent of claim 2, wherein the point at which the slopes of thetangent lines of the one of the plating layers are opposite to eachother is a point at which slopes of tangent lines change from a negativevalue to a positive value.
 5. The multilayer ceramic electroniccomponent of claim 1, wherein the at least one point at which slopes oftangent lines of one of the first layers are opposite to each other, isdisposed in a region within a range of ±0.2 BW around a point (0.5 BW)that is a halfway point of an overall width BW of the electrode layersdisposed on the first surface or the second surface of the ceramic body.6. The multilayer ceramic electronic component of claim 1, wherein theoverall width BW of the electrode layers disposed on the first surfaceand the second surfaces of the ceramic body is the width of the firstlayer.
 7. The multilayer ceramic electronic component of claim 1,wherein the plating layers cover end portions of the first layer.
 8. Themultilayer ceramic electronic component of claim 1, wherein the secondlayer covers a corner portion of the ceramic body.
 9. The multilayerceramic electronic component of claim 1, wherein the width of the secondlayer disposed on the first surface or the second surface of the ceramicbody is a width, in the second direction, of the second layer disposedon the first surface or the second surface of the ceramic body, and thewidth of the first layer disposed on the first surface or the secondsurface of the ceramic body is a width, in the second direction, of thefirst layer disposed on the first surface or the second surface of theceramic body.
 10. The multilayer ceramic electronic component of claim1, wherein one of the dielectric layers has a thickness of 0.4micrometer or less.
 11. The multilayer ceramic electronic component ofclaim 10, wherein each of the dielectric layers has a thickness of 0.4micrometer or less.
 12. The multilayer ceramic electronic component ofclaim 10, wherein one of the internal electrodes has a thickness of 0.4micrometer or less.
 13. The multilayer ceramic electronic component ofclaim 1, wherein one of the internal electrodes has a thickness of 0.4micrometer or less.
 14. The multilayer ceramic electronic component ofclaim 1, wherein the ceramic body includes an active portion in whichcapacitance is formed by including the plurality of internal electrodesdisposed to oppose each other with the dielectric layers interposedtherebetween, and cover portions disposed above and below the activeportion, and a thickness of each of the cover portions is 20 micrometersor less.
 15. The multilayer ceramic electronic component of claim 1,wherein the point at which the slopes of the tangent lines of the one ofthe first and second layers are opposite to each other is a point atwhich slopes of tangent lines change from a negative value to a positivevalue.
 16. The multilayer ceramic electronic component of claim 15,wherein one of the dielectric layers has a thickness of 0.4 micrometeror less.
 17. The multilayer ceramic electronic component of claim 1,wherein the at least one point is disposed in the region within therange of ±0.2 BW, in the second direction, around a point (0.5 BW) thatis a halfway point of the overall width BW, in the second direction, ofthe electrode layers disposed on the first surface or the second surfaceof the ceramic body.
 18. The multilayer ceramic electronic component ofclaim 1, wherein the electrode layers include a conductive metal and aglass.
 19. The multilayer ceramic electronic component of claim 1,wherein the plating layers include a nickel plating layer and a tinplating layer.
 20. A multilayer ceramic electronic component comprising:a ceramic body including dielectric layers and a plurality of internalelectrodes disposed to face each other with the dielectric layersinterposed therebetween, the ceramic body having a first surface and asecond surface opposing each other in a first direction, a third surfaceand a fourth surface connected to the first surface and the secondsurface and opposing each other in a second direction, and a fifthsurface and a sixth surface connected to the first surface to the fourthsurface and opposing each other in a third direction; and an externalelectrode disposed on external surfaces of the ceramic body andconnected to the internal electrodes, wherein the external electrodeincludes electrode layers connected to the internal electrodes and theelectrode layers extend to the first surface and the second surface ofthe ceramic body, the electrode layers are disposed on one of the thirdsurface and the fourth surface, and include a first layer connected tothe internal electrodes and a second layer disposed on the first layerin such a manner that a width of the second layer disposed on the firstsurface or the second surface of the ceramic body is smaller than awidth of the first layer disposed thereon, at least one point, at whichslopes of tangent lines of one of the first and second layers areopposite to each other, is disposed on the first surface or the secondsurface of the ceramic body, and each of the first layer and the secondlayer includes a conductive metal and a glass.